/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dolphinscheduler.service.cron;

import com.cronutils.model.Cron;
import com.cronutils.model.definition.CronDefinitionBuilder;
import com.cronutils.model.time.ExecutionTime;
import com.cronutils.parser.CronParser;
import lombok.NonNull;

import static com.cronutils.model.CronType.QUARTZ;
import static org.apache.dolphinscheduler.common.constants.CommandKeyConstants.CMD_PARAM_COMPLEMENT_DATA_SCHEDULE_DATE_LIST;
import static org.apache.dolphinscheduler.common.constants.Constants.COMMA;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.day;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.hour;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.min;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.month;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.week;
import static org.apache.dolphinscheduler.service.cron.CycleFactory.year;

import org.apache.dolphinscheduler.common.constants.Constants;
import org.apache.dolphinscheduler.common.enums.CycleEnum;
import org.apache.dolphinscheduler.common.lifecycle.ServerLifeCycleManager;
import org.apache.dolphinscheduler.common.utils.DateUtils;
import org.apache.dolphinscheduler.dao.entity.Schedule;
import org.apache.dolphinscheduler.service.exceptions.CronParseException;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Collectors;

/**
 * // todo: this utils is heavy, it rely on quartz and corn-utils.
 * cron utils
 */
public class CronUtils {

  private CronUtils() {
    throw new IllegalStateException("CronUtils class");
  }

  private static final Logger logger = LoggerFactory.getLogger(CronUtils.class);

  private static final CronParser QUARTZ_CRON_PARSER =
      new CronParser(CronDefinitionBuilder.instanceDefinitionFor(QUARTZ));

  /**
   * parse to cron
   *
   * @param cronExpression cron expression, never null
   * @return Cron instance, corresponding to cron expression received
   */
  public static Cron parse2Cron(String cronExpression) throws CronParseException {
    try {
      return QUARTZ_CRON_PARSER.parse(cronExpression);
    } catch (Exception ex) {
      throw new CronParseException(String.format("Parse corn expression: [%s] error", cronExpression), ex);
    }
  }

  /**
   * get max cycle
   *
   * @param cron cron
   * @return CycleEnum
   */
  public static CycleEnum getMaxCycle(Cron cron) {
    return min(cron).addCycle(hour(cron)).addCycle(day(cron)).addCycle(week(cron)).addCycle(month(cron))
        .addCycle(year(cron)).getCycle();
  }

  /**
   * get min cycle
   *
   * @param cron cron
   * @return CycleEnum
   */
  public static CycleEnum getMiniCycle(Cron cron) {
    return min(cron).addCycle(hour(cron))
        .addCycle(day(cron))
        .addCycle(week(cron))
        .addCycle(month(cron))
        .addCycle(year(cron))
        .getMiniCycle();
  }

  /**
   * get max cycle
   *
   * @param crontab crontab
   * @return CycleEnum
   */
  public static CycleEnum getMaxCycle(String crontab) {
    try {
      return getMaxCycle(parse2Cron(crontab));
    } catch (CronParseException ex) {
      throw new RuntimeException("Get max cycle error", ex);
    }
  }

  public static List<ZonedDateTime> getFireDateList(@NonNull ZonedDateTime startTime,
                                                    @NonNull ZonedDateTime endTime,
                                                    @NonNull String cron) throws CronParseException {
    return getFireDateList(startTime, endTime, parse2Cron(cron));
  }

  /**
   * gets all scheduled times for a period of time based on not self dependency
   *
   * @param startTime startTime
   * @param endTime   endTime
   * @param cron      cron
   * @return date list
   */
  public static List<ZonedDateTime> getFireDateList(@NonNull ZonedDateTime startTime,
                                                    @NonNull ZonedDateTime endTime,
                                                    @NonNull Cron cron) {
    List<ZonedDateTime> dateList = new ArrayList<>();
    ExecutionTime executionTime = ExecutionTime.forCron(cron);

    while (!ServerLifeCycleManager.isStopped()) {
      Optional<ZonedDateTime> nextExecutionTimeOptional = executionTime.nextExecution(startTime);
      if (!nextExecutionTimeOptional.isPresent()) {
        break;
      }
      startTime = nextExecutionTimeOptional.get();
      if (startTime.isAfter(endTime)) {
        break;
      }
      dateList.add(startTime);
    }

    return dateList;
  }

  /**
   * Gets expect scheduled times for a period of time based on self dependency
   *
   * @param startTime startTime
   * @param endTime   endTime
   * @param cron      cron
   * @param fireTimes fireTimes
   * @return nextTime execution list
   */
  public static List<ZonedDateTime> getSelfFireDateList(@NonNull ZonedDateTime startTime,
                                                        @NonNull ZonedDateTime endTime, @NonNull Cron cron,
                                                        int fireTimes) {
    List<ZonedDateTime> executeTimes = new ArrayList<>();
    ExecutionTime executionTime = ExecutionTime.forCron(cron);
    while (fireTimes > 0) {
      Optional<ZonedDateTime> nextTime = executionTime.nextExecution(startTime);
      if (!nextTime.isPresent()) {
        break;
      }
      startTime = nextTime.get();
      if (startTime.isAfter(endTime)) {
        break;
      }
      executeTimes.add(startTime);
      fireTimes--;
    }
    return executeTimes;
  }

  public static List<Date> getSelfFireDateList(@NonNull final Date startTime,
                                               @NonNull final Date endTime,
                                               @NonNull final List<Schedule> schedules) throws CronParseException {
    ZonedDateTime zonedDateTimeStart = ZonedDateTime.ofInstant(startTime.toInstant(), ZoneId.systemDefault());
    ZonedDateTime zonedDateTimeEnd = ZonedDateTime.ofInstant(endTime.toInstant(), ZoneId.systemDefault());

    return getSelfFireDateList(zonedDateTimeStart, zonedDateTimeEnd, schedules).stream()
        .map(zonedDateTime -> new Date(zonedDateTime.toInstant().toEpochMilli()))
        .collect(Collectors.toList());
  }

  /**
   * gets all scheduled times for a period of time based on self dependency
   * if schedulers is empty then default scheduler = 1 day
   */
  public static List<ZonedDateTime> getSelfFireDateList(@NonNull final ZonedDateTime startTime,
                                                        @NonNull final ZonedDateTime endTime,
                                                        @NonNull final List<Schedule> schedules) throws CronParseException {
    List<ZonedDateTime> result = new ArrayList<>();
    if (startTime.equals(endTime)) {
      result.add(startTime);
      return result;
    }

    // support left closed and right closed time interval (startDate <= N <= endDate)
    ZonedDateTime from = startTime.minusSeconds(1L);
    ZonedDateTime to = endTime.plusSeconds(1L);

    List<Schedule> listSchedule = new ArrayList<>();
    listSchedule.addAll(schedules);
    if (CollectionUtils.isEmpty(listSchedule)) {
      Schedule schedule = new Schedule();
      schedule.setCrontab(Constants.DEFAULT_CRON_STRING);
      listSchedule.add(schedule);
    }
    for (Schedule schedule : listSchedule) {
      result.addAll(CronUtils.getFireDateList(from, to, schedule.getCrontab()));
    }
    return result;
  }

  /**
   * get expiration time
   *
   * @param startTime startTime
   * @param cycleEnum cycleEnum
   * @return date
   */
  public static Date getExpirationTime(Date startTime, CycleEnum cycleEnum) {
    Date maxExpirationTime = null;
    Date startTimeMax = null;
    try {
      startTimeMax = getEndTime(startTime);

      Calendar calendar = Calendar.getInstance();
      calendar.setTime(startTime);
      switch (cycleEnum) {
        case HOUR:
          calendar.add(Calendar.HOUR, 1);
          break;
        case DAY:
          calendar.add(Calendar.DATE, 1);
          break;
        case WEEK:
          calendar.add(Calendar.DATE, 1);
          break;
        case MONTH:
          calendar.add(Calendar.DATE, 1);
          break;
        default:
          logger.error("Dependent process definition's  cycleEnum is {},not support!!", cycleEnum);
          break;
      }
      maxExpirationTime = calendar.getTime();
    } catch (Exception e) {
      logger.error(e.getMessage(), e);
    }
    return DateUtils.compare(startTimeMax, maxExpirationTime) ? maxExpirationTime : startTimeMax;
  }

  /**
   * get the end time of the day by value of date
   *
   * @return date
   */
  private static Date getEndTime(Date date) {
    Calendar end = new GregorianCalendar();
    end.setTime(date);
    end.set(Calendar.HOUR_OF_DAY, 23);
    end.set(Calendar.MINUTE, 59);
    end.set(Calendar.SECOND, 59);
    end.set(Calendar.MILLISECOND, 999);
    return end.getTime();
  }

  /**
   * get Schedule Date
   *
   * @param param
   * @return date list
   */
  public static List<Date> getSelfScheduleDateList(Map<String, String> param) {
    List<Date> result = new ArrayList<>();
    String scheduleDates = param.get(CMD_PARAM_COMPLEMENT_DATA_SCHEDULE_DATE_LIST);
    if (StringUtils.isNotEmpty(scheduleDates)) {
      for (String stringDate : scheduleDates.split(COMMA)) {
        result.add(DateUtils.stringToDate(stringDate.trim()));
      }
      return result;
    }
    return null;
  }

}
